Brake mechanism



Feb. 9, 1960 K. R. DuRsT ET Aa.

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United States Patent() BRAKE MECHANISM Kenneth. R. Durst, Troy, and Richard E. Frazier, Pleasant Hill, Ohio, assignors to The B. F. Goodrich Company, New York, N.Y., a corporation of New York Application September 29, 1958, Serial No. 763,937

' 1 claim. (cl. iss-73) This invention relates to an improved brake mechanism and to an assembly of such brake mechanism with a wheel. A

The present invention provides a relatively inexpensive, light brake mechanism especially suitable for light low speed aircraft of the type designed for only several passengers. The brake is a disc type brake of the so-called spot brake class in which the rotatable braking member carried by the wheel is a full annulus and the nonrotatable braking members engageable therewith are equivalent in area to only a small sector of the annular rotatable member. The non-rotatable braking members in this new brake are hinged to a rigid mounting member that is rigidly engaged to the wheel axle structure. These hingedmembers extend generally radially of the wheel to embrace the opposing surfaces of the rotatable member. The hinged members are adapted to be swung pivotally into engagement with the rotatable braking members by an actuating mechanism which exerts braking force on the hinged braking members at a region of each intermediate their respective hinge portions and their braking faces.

This brake structure has been found to have substantially equal lining wear in the radial direction of the lining, notwithstanding the fact that the braking pressure is exerted by hinged members. This'advantageous result occurs apparently before the deflection of the outer region of the hinge members tends to compensate for the differential rate of lining wear normally expected in its radial l direction.

The brake is advantageously actuatedV hydraulically by mutually engageable actuation members which are supported solely by the hinge members. The actuated members are particularly designed and arranged so that the brake may be very simply adjusted to compensate for lining wear and the slack which would otherwise result.

A brake mechanism together with a wheel assembled therewith which is constructed in accordance with and embodying the present invention is shown in the accompanying drawings.

In the drawings:

Fig. 1 is a view of the wheel and brake assembly looking in the axial direction of the wheel;

Fig. 2 is a cross-sectional view taken on the line 2-2 Aof Fig. l, the brake mechanism being shown in released position; and

Fig. 3 is a detailed fragmentary cross-sectional view taken on the line 3-3 of Fig. 1, but with the brake parts shown in their engaged position.

The assembly comprises a brake mechanism mounted on an axle structure 11 on which a wheel 12 is mounted for rotation relative to the axle. The wheel 12 carries an annular brake disc 13 secured to one of its bead flanges 14 by bolts 15 so that the disc 13 rotates with the wheel.

The brake mechanism includes a rigid mounting plate which is fastened by bolts 21 to a torque flange 22 which is integral with the non-rotatable axle 11.

2,924,301 Patented' Feb;l 9,111.6(71' The mounting plate 20 has attached to it two nonv rotatable lining carrier members 24 and 25 which extend from one edge of the mounting plate 20 radially outward to embrace the opposing plane surfaces of the brake disc 13. Near the outer end of each lining carrier 24 and 25 there is attached a suitable friction lining material y26 which directly engages the opposing radial faces of the brake disc 13 and which serves as the braking faces of the lining carriers. The lining carriers, ofcourse, are the engageable non-rotatable brake members.

The lining carriers 24 and 25 each have a hingeconnection with the mounting plate 20. As shown in Fig. 1 .the mounting plate 20 at its upper edge has a pair of aligned lug members 2821 and 28b. The lower edge of the inner lining carrier 25 includes a narrow lug 29 which fits between the lugs 28a and 28h. The outer or'left (Fig. 2) lining carrier 24 at its lower edge is formedwith widely spacedlugs 30a and 30b which externally` embrace the lugs 25a and Zb. A common hinge pin V32V extends through coaxial holes 33 in each lug which register with each other when the lugs are assembled properly as shown 1n Fig. 1. With tms arrangement'the lining carriers 24 and 25 may 'be moved or swung pivotally about the hinge pin 32 in an arc relative to the `brake mounting member 20.

l In this embodiment of the invention,r the brake member is hydraulically actuated by a hydraulic unit 36 carried by the lining carriers 24 and 25. The hydraulicV actuating unit 36 includes two main parts, a cup shaped casing member'37 inside of which a piston member 38 is slidable and is maintained in sealed engagement by peripheral O-ring. Between the piston 38 and the casing 37 there is a iiuid chamber 40 and a connection 41 through the casing 37 through which uid pressure may be introduced into chamber 40.

through `the center opening of disc 13, andl then through l the lining carrier 25fin the manner shown in Fig. 3. It may be'noted in Fig. 3 that the stud members ortdra'w rods 27 extend loosely lthrough holes in the lining carriers 24 and `251,respectively', Vand the opposing outer ends of the draw rod are fastened by nuts 44 and 45, respectively.' It may be noted in Fig. l that the draw rods 27 are parallel to each other and at equal radial distances from tne central rotational axis of the wheel.

Between the lining carriers 24 and 25 eachv draw rod is surrounded by a spring 48 which is caged under compression between the lining carriers so as to bias the lining carriers outwardly away from each other. The spring thus urges lining carrier 25 against its retaining nut 44 and urges lining carrier 24 snugly against the bottom of member 37a of the actuation casing 37 when the brake is released as in Fig. 2. It is to be noted particularly that member 37a is not integrally connected to the adjoining lining carrier 24. The piston member 38 of the actuating mechanism includes acenter shank member 50 (Figs. 2 and 3) which extends through an opening51 in closure member 37a and bears directly against the lining carrier 24 in plane of the draw rod members 27.

The parts of the brake mechanism in Fig. 2 are shown in their normally released position in which the lining carriers 24-25 are spaced away from the opposing radial faces of the disc 13 by the biasing springs 48. In response to the introduction of fluid pressure into chamber 40, the shank portion 50 of the piston member 38 pushes` n animaux directly against lining' carrier 24 and simultaneously the -V 37o willbeidisplacedislightly` away from. the lining car-- rier 24 when the; brake is fullyactuated, as shown Fig. El'.l On releasewof pressure the biasing springs 48-expand toreturn-`A the parts to the position shownin Fig.` 2.` Y

Itis to be notedthat the actuation force` applied'I through the drawrods 27- and4 throughthe shank portion M50 of pistonu 38 isfacommonv plane intermediaterthefriction liningor braking `faces 26` of the lining carriers and their hinged side. By applying the braking force in this location 'to the A braking carriers, the, outer portions of the carriers radially beyond the forceapplying plane tend to deiect somewhat away from the brake `disc 13 so that a i nected' to :one ofrsaidyhinged `braking members at a region 1 4slightly higher braking pressure is encountered near the. a

inner radial circumference ofthe brake disc 13than in the regions near the radial outer margins ofthe brake disc.V This pressure differential in a radial direction across the: disc` appears vto compensate Afor the fact that lining wear ispnormally moresevere near the faster moving radially outer portion of` the., brake disc. Thus wear on the lining members 26 in this brakeidesign is4 unusually even`notwithstanding the, fact that the lining, members 14 and 25` are swung pivotally into engagement with the brake disc13. n

. In the fully released pos'tion of the actuation mechani'srn it may be noted as` shown in Fig. 2 that the piston member` 38V is seatedsnugly against the bottom of the casing member `37 and with its `shank seatedtirmly against the lining carrier 24. To adjust this brake for wear itis merely necessaryto screw the casingmernber Y37 down further and further onto the peripheral threads of the end closuremember 37a. By'threading the casing member 37 onto` member 37a in this mannentherpiston 38 audits shank,50 are urged forwardly against the linf ing carrier 2.4.` Atthe same time such threading moves the closure member 37a away from the liningcarrier 24,

thereby `drawing the opposing lining carrier V toaposil tionwhereinvits lining 26 is closer to the radial opposing face ofthe brake disc 13.` d By this simple :threaded adjust mentA ofthe casing member 37 both lining carriersV may bereasily adjusted to` compensate for wear of their respective linings 26. l* 1 j Variations in the construction disclosed may be made withinthe scope of the appended claims.'

j'chamber'for;relativefdisplacement so that said external actuationgmember through saidwdraw rods pulls one W'ecla-mr (t A wheel and brake assembly comprising `a wheel adapted for rotation on a non-rotatable axle mechanism,

a braking disc disposed in a'plane'coaxial with the rotational axis of the wheel and adapted for rotation with the wheel, a brake mountingange on said axle, a brake mounting member engaged, with said flange and including 'a pair of non-rotatable brake members each in hinged .n

engagement with` the brakeimountingfgmember and emsite sides of said disc, and Ibrake actuating mechanism comprising two inter-engaging actuation members one;

externally embracing the other and both cooperating to define a uid pressure chamber, a pair of draw rods conthereof'between its brakingface and itsi hinged'portion,- the draw rods `extending in parallelism through the opposing: hinged ymember in the. region intermediate its'. braking 4face and itshinged :portion and being" connected to the externalone of; said actuation members, the internal one j hingedv brake member forcibly against` one side of said rotatable` braking member and; soL that. the. internal actuation` member engages; said opposing hinged, brake mem-` rodj between saidhnged brake: members. for biasing; said hinged members `apart from `each other.

i ReferenesfCited inthe le of this patent UN'IrED STATES PATENTSr UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No I, 2,924 7 301 February 9 1960 Kenneth R. Durs-t et al.

It is hereby certified t s in the vprinted specification e above numbered patent requiring correction and 'that the said Letters t should read as corrected below.

hat error appear Paten Column l, line 4l for "before" read because Signed and sealed this 16th day of August 1960.

(SEAL) Attest: R KARL H. AXLINE i ROBERT C. WATSON Attesting Oficer Commissioner Of Patents 

